Switch assembly



June 26, 1956 G. M. EULER SWITCH ASSEMBLY Filed Jan. 26, 1954 1 .Pllillllllll [r2 ven tar". George M Eu/er', by

/7/ls Attorney United States Patent SWITCH ASSEMBLY George M. Euler,Morrison, Ill., assignor to General Electric Company, a corporation ofNew York Application January 26, 1954, Serial No. 406,258

3 Claims. (Cl. 200153) This invention relates to switch assemblies andmore particularly to the combination of a switch and actuating meanstherefore.

There are frequent applications which require the actuation of a switchin response to physical movement of some other device. For example, in asump pump installation, it is necessary to actuate a switch to start thepump motor when the water level in the sump rises to a predeterminedupper level and to again actuate the switch to shut off the motor whenthe water level has fallen to a predetermined lower level. Floats ordisplacement weights are conventionally used to detect the water leveland the switch must thus be actuated by physical movement of theassociated float or displacement Weight. It is desirable that thisswitch actuating mechanism be simple, reliable, and inexpensive, and itis further desirable that it be usable with a commercially availableswitch.

It is therefore an object of this invention to provide an improvedswitch assembly incorporating the desirable features set forth above.

Further objects and advantages of this invention will become apparent byreference to the following description and the accompanying drawing, andthe features of novelty which characterize this invention will bepointed out with particularity in the claims annexed to and forming apart of this specification.

This invention in its broadest aspects provides a switch including anactuating member having a first normal position and a second position. Aspring is provided which engages the switch actuating member and anotherpivoted actuating member is provided which engages the spring. The otheractuating member is movable under the influence of an external force todeflect the spring member thereby permitting the switch actuating memberto move to its normal position.

In the drawing,

Fig. l is an elevational view showing a sump pump and motor equippedwith the improved switch assembly of this invention;

Fig. 2 is a side elevational view, partly in section, illustrating theimproved switch assembly of this invention and taken along the line 22of Fig. 3; and

Fig. 3 is atop view, partly broken away, of the improved switch assemblyof Fig. 2.

Referring now to Fig. 1, there is shown a sump pump 1 arranged in sump 2and being driven by a suitable elec tric motor 3. It will be readilyunderstood that the sump pump 1 and motor 3 as shown here do not form apart of this invention and that any desired combination of motor andpump may be used. The improved switch assembly of this invention isshown generally at 4 and is used to respectively start and stop pumpmotor 3 in response to predetermined changes in the level 5 of theliquid and the sump 2. In the arrangement shown, a pair of displacementweights 6 are suspended by means of a flexible wire '7 from actuatingmember 8 of switch 4. Weights 6 are heavier than the fluid in the sump 2and in accordance with well known physical principles, their 2,752,461Patented June 26, 1956 apparent weight changes when they are immersed influid. Thus, as the level 5 of the fluid in sump 2 rises above weights6, their apparent weight is lessened thus lowering the downward forceapplied to actuating member 8 and in turn actuating switch 9, as will behereinafter more fully described. Actuation of switch 9 which isconnected in circuit with motor 3, starts the motor which operates sumppump 1 to pump fluid out of sump 2 through discharge pipe 10. When thelevel 5 of the fluid in sump 2 falls to a predetermined lower level sothat weights 6 are substantially above the level 5, their apparentincrease in weight exerts a greater downward force on actuating member 8thus actuating switch 9 to turn off motor 3.

Referring now to Fig. 2, switch assembly 4 includes a small snap actingswitch 9, which may be the type shown in Patent No. 2,332,911 to GeorgeM. Hausler issued October 26, 1943 and assigned to the assignee of' thepresent application. Switch 9 is secured to the upper surface of amounting member 11, as by means of screws 12, which has an opening 13formed therein through which actuating button 14 of switch 9 projects. Aspring mounting member 15 is provided having one end 16 secured to theside of switch mounting member 11 opposite from switch 9 in any suitablemanner, as by the same screws 12 which secure switch 9 to the mountingmember 11. A cantilever spring 17 is provided having its end 18 securedto spring mounting member 15 adjacent its free end 19 in any suitablemanner, as by riveting at 2h. Spring 17 engages actuating button 14 ofswitch 9 which has a normal position as shown in dashed lines and asecond position as shown in solid lines in Fig. 2. In the embodimentshown in Fig. 2, spring 17 serves normally to bias switch actuatingbutton 14 into its second position as shown.

In order to provide for adjusting the force applied to switch actuatingbutton 14 by spring 17, a projection 21 is formed on one end of switchmounting member 11 and a screw 22 connects projection 21 and end 19 ofspring mounting member 15. It will be readily seen that by turning screw22 in one direction, end 19 of spring mounting member 15 will be movedtoward projection 21 of switch mounting member 11 thus lessening thepressure applied to switch actuating button 14 by cantilever spring 17and, conversely, turning the screw 22 in the opposite direction willmove end 19 of spring mounting member 15 away from projection 21 thusincreasing the pressure which the spring 17 applies to switch actuatingbutton 14.

Switch mounting member 11 has a pair of downwardly extending portions 23formed on each side thereof and a base member 24 is attached thereto.Base member 24 has an opening 25 formed therein for a purpose now to bedescribed. Actuating member 8 is provided having its end 27 pivoted inopenings 28 in mounting member portions 23, as by means of a transverseportion 29. A notch 30 is formed in the end 31 in which the end 32 ofcantilever springs 17 is seated. Actuating member 8 has a portion 26extending from its end 31 and through opening 25 in base 24. Wire 7which supports displacement weights 6 is attached to the end ofextension 26 of actuating member 8.

In operation, assuming that the water level 5 in sump 2 has fallensufliciently to substantially expose displacement weights 6, theresultant downward force exerted by wire 7 on actuating member 8 willcause it to move to the position as shown by the dashed lines 33 in Fig.2 thus moving cantilever spring 17 to the position shown in dashed linesand allowing actuating button 14 of switch 9 to move to its normalposition in which its contacts are open and the motor 3 is deenergized.When the level 5 of the fluid in sump 2 rises to a predetermined level,the

downward force exerted by wire 7 on actuating member 8 will be overcomeby the upward force exerted by cantilever spring 17 thus movingactuating member 8 to the position shown in solid lines in Fig. 2 andmoving actuator button 14 of switch 9 to its second or contacts closedposition to energize motor 3. It will be readily seen that the waterlevel at which actuator 8 moves to its solid line position as shown inFig. 2 thereby to permit cantilever spring 17 to move switch actuatorbutton 14 to its second or contacts closed position is determined byadjustment of screw 22 which adjusts the upward force exerted bycantilever spring 17. The lower level at which the actuator member 8moves to its dashed line position 33 as shown in Fig. 2 is determined bythe spacing of the upper weight from the lower weight.

While the improved switch assembly of this invention has been shown inconnection with a sump pump, it will be readily understood that it isusable in other installations which require actuation of the switch inresponse to an external force. It will also be readily apparent thatthis invention provides an improved and simplified switch assembly whichadapts a small commercially available snap acting switch to a widevariety of uses.

While I have shown and described a particular embodiment of thisinvention, further modifications and improvements will occur to thoseskilled in the art. I desire that it be understood therefore that thisinvention is not limited to the forms shown and I intend in the appendedclaims to cover all modifications which do not depart from the spiritand scope of this invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A switch assembly comprising a snap acting switch including anactuating button having a first normal position and a second position, amounting member having an opening formed therein, said switch beingsecured to one side of said mounting member with said actuating buttonextending through said opening, a spring mounting member having one endsecured to said first named mounting member, a cantilever spring memberhaving one end secured to said spring mounting member adjacent the otherend thereof and engaging said switch actuating button, said first namedmounting member having an extension formed on one end thereof, screwmeans engaging said mounting member extension and said other end of saidspring mounting member for adjusting the pressure applied on said switchactuating button by said spring, said first named mounting member havinga pair of projections extending on either side thereof away from saidswitch, a base member secured to said projections, and another actuatingmember engaging the other end of said spring member and having its otherend pivoted, said base member having an opening formed therein, saidother actuating member having an extension extending through said basemember opening, said other actuating member extension being adapted tobe moved to a first position under the influence of an external force todeflect said spring member and thereby permitting said switch actuatingbutton to move said normal position.

2. A switch assembly comprising a switch including an actuating memberhaving a first normal position and a second postion, a mounting memberfor said switch, a cantilever spring member having one end secured tosaid mounting member and engaging said switch actuating member andnormally biasing the same to said second position, a base member spacedfrom said mounting member, and another actuating member having one endengaging the other end of said spring member positioned intermediatesaid mounting member and said base memher and having its other endpivoted, said base member having an opening formed therein, said otheractuating member having an extension formed on said one end thereof andextending through said base member opening, said other actuating memberextension being adapted to be moved t a first position under theinfluence of an external. force to deflect said spring member therebypermitting said switch actuating member to move to said normal position,said spring member returning said other actuating member to a normalposition and moving said switch actuating member to said second positionwhen said force is removed from said other actuating member extension.

3. A switch assembly comprising a snap acting switch including anactuating button having a first normal position and a second position, amounting member having an opening formed therein, said switch beingsecured to one side of said mounting member with said actuating buttonextending through said opening, a spring mounting member having one endsecured to said first named mounting member, a cantilever spring memberhaving one end secured to said spring mounting member adjacent the otherend thereof and engaging said switch actuating button and normallybiasing the same to said secend position, said first named mountingmember having an extension formed on one end thereof, screw meansengaging said mounting member extension and said other end of saidspring mounting member for adjusting the pressure applied on said switchactuating button by said spring, said first named mounting member havinga pair of projections extending on either side thereof away from saidswitch, a base member secured to said projections, and another actuatingmember having one end engaging the other end of said spring memberpositioned intermediate said first named mounting member and said basemember and having its other end pivoted to said projections, said basemember having an opening formed therein, said other actuating memberhaving an extension formed on said one end thereof and extending throughsaid base member opening, said other actuating member extension beingadapted to be moved to a first position under the influence of anexternal force to deflect said spring member thereby permitting saidswitch actuating button to move to said normal position, said springmember returning said other actuating member to a normal position andmoving said switch actuating button to said second position when saidforce is removed from said other actuating member or extension.

References Cited in the file of this patent UNITED STATES PATENTS842,554 Johnson Jan. 29, 1907 2,302,923 Zimarik Nov. 24, 1942 2,338,365Thorp et a1. Jan. 4, 1944 2,547,765 Lund Apr. 3, 1951 2,612,368 RansomeSept. 30, 1952 FOREIGN PATENTS 200,810 Switzerland Jan. 16, 1939

